<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1 align="center">一级标题</h1>
<br>
<hr>
<h2> <u>二级标题</u> </h2>

<div>第一个div</div>
<div>第二个div</div>


<span>第一个span</span>
<span>第二个span</span>
</body>
</html>